Points and Line Segments

Transcription

1 Points and Line Segments Objective To guide children as they define, name, and draw line segments. epresentations etoolkit lgorithms Practice M acts Workshop Game amily Letters ssessment Management ommon ore State Standards urriculum ocal Points Interactive Teacher s Lesson Guide Teaching the Lesson Ongoing Learning & Practice ifferentiation Options Key oncepts and Skills Solve number stories using addition facts. [Operations and omputation Goal 1] onnect points in a sequence to draw line segments. Use a straightedge to draw a line segment. Key ctivities hildren define and name points and line segments with letter labels. They also practice drawing line segments with a straightedge according to a code. Ongoing ssessment: Recognizing Student chievement Use an xit Slip (Math Masters, page 415). Key Vocabulary point straightedge line segment endpoint Materials Math Journal 1, p. 113 My Reference ook, p. 50 Home Link 5 1 Math Masters, p. 415 straightedge dvance Preparation Practicing with +, act Triangles +, act Triangles hildren practice addition and subtraction facts using act Triangles. Math oxes 5 2 Math Journal 1, p. 114 hildren practice and maintain skills through Math ox problems. Home Link 5 2 Math Masters, p. 127 hildren practice and maintain skills through Home Link activities. RINSS Making Geoboard esigns Math Masters, p. 128 geoboard rubber bands hildren use a geoboard to explore making designs with line segments. NRIHMNT reating a Line Segment esign Math Masters, p. 129 straightedge crayons hildren explore drawing line segments in a sequence. Teacher s Reference Manual, Grades 1 3 pp. 131, Unit 5 3- and 2- Shapes

2 Getting Started Mathematical Practices SMP1, SMP2, SMP5, SMP6 ontent Standards 2.O.1, 2.O.2 Mental Math and Reflexes Pose number stories with harder addition and subtraction facts: lexi has 8 toy cars. Theo has 7 toy cars. How many do they have in all? 15 toy cars Jillian had 9 crayons. She found 6 more. How many crayons in all? 15 crayons Shantell brought 14 lollipops to school. She gave away 8 during lunch. How many does she have now? 6 lollipops Maya went down the slide 17 times during recess. Jason went down 9 times. Maya went down the slide how many more times than Jason? 8 times Math Message Write a sentence that has the word point or points in it. Home Link 5 1 ollow-up Review the rule and write it on the board. sk volunteers to draw shapes that fit that rule. 1 Teaching the Lesson Math Message ollow-up WHOL-LSS ISUSSION Write a few of the children s sentences on the board. If interest in this activity is high, add a few sentences of your own. or example: My pencil has a sharp point. The football team scored 21 points. This number has a decimal point in it. an you point out the picture you like the best? iscuss the meaning of the word point in geometry an exact location in space, the tiniest part of a figure, an object without length, something represented by a dot, and so on. iscussing How Points re Named WHOL-LSS raw five dots on the board. sk someone to choose one of the dots and to tell you which one it is without pointing to it. He or she will probably have a hard time doing this. xplain that an easy way to talk about points is to give them labels. Points are usually labeled with capital letters, such as,, and. Label each of the dots on the board, calling them by name as you do so: Point, Point, and so on. Links to the uture This is a preliminary exposure to drawing and labeling points. Identifying and drawing points are Grade 3 Goals. Lesson

3 NOT There is a difference between a straightedge and a ruler. straightedge is a tool for drawing straight lines. ruler is both a measuring and a drawing tool. ruler is a straightedge, but a straightedge may or may not be a ruler, depending on whether it is divided into unit intervals. This distinction need not be made for children at this time. djusting the ctivity LL onsider posting point, straightedge, line segment, and endpoint on the Word Wall so children can refer to them as necessary. Include a picture and a written description from the glossary next to each word. UITORY KINSTHTI TTIL VISUL efining and Naming Line Segments (Math Masters, p. 415; My Reference ook, p. 50) WHOL-LSS sk children what they think straight means. Not curved or goes in one direction are good responses. Point out that a straightedge is a tool used for drawing straight lines. On blank sheets of paper, have children draw two dots as you do the same on the board. Label the dots and. Then demonstrate how to draw a straight line connecting them: Place the straightedge just under the dots and draw from point to point, not from letter to letter, and not past the points. Tell children that they just drew a line segment whose endpoints are points and. The segment can be called line segment or line segment the names of the endpoints can be in either order. Write _ and _ on the board and say that sometimes the symbols are used for line segment or line segment. or a summary of these concepts, read My Reference ook, page 50 with your class. sk children to draw three points (that are not in a straight line) on their papers and to label each point with a different letter. xplain that in any problem or example, all the points must have different names; two points may not have the same letter label. Have children use a straightedge to connect each of the three points to each of the other points. sk children to name the shape they have formed. triangle rawing a line segment labeled Student Page Ongoing ssessment: Recognizing Student chievement xit Slip Use an xit Slip (Math Masters, page 415) to assess children s ability to use a straightedge to draw a line segment. Have children use a straightedge to draw line segment. hildren are making adequate progress if they are able to use the straightedge to draw a line segment. Some children may indicate the endpoints and still others may label the endpoints. rawing Line Segments with a Straightedge (Math Journal 1, p. 113) PRTNR Math Journal 1, p. 113 The first part of the journal page shows points connected by line segments, along with a code that specifies the sequence in which the points have been connected. or example, the code means: irst draw a line segment from to, then a line segment from to, and finally one from to. Give partners 2 or 3 minutes to figure out the codes. Then go over the three codes with the class. In the second part of the activity, children draw line segments according to given codes. Partners can work on these problems while you circulate and assist children who need help. 324 Unit 5 3- and 2- Shapes

4 2 Ongoing Learning & Practice Practicing with +, - act Triangles Have children practice addition and subtraction facts using their act Triangles. s children practice, ask them to sort the act Triangles into two piles facts they know from memory and facts that need more practice. Have them write down the facts for which they need practice. ate LSSON 5 2 Math oxes 1. ill in the missing numbers. Rule Which number is an odd number less than 50? ircle the best answer Student Page Time 2. lex s Reading Log ecember November October September ooks Read Key: = 1 book How many more books did lex read in ecember than in September? 5 4. Solve = 14 Write the turn-around fact = 14 Unit Math oxes 5 2 (Math Journal 1, p. 114) INPNNT Mixed Practice Math oxes in this lesson are paired with Math oxes in Lesson 5-4. The skill in Problem 6 previews Unit 6 content What time is it? 2 : 30 In 15 minutes it will be 2 : Math Journal 1, p red jelly beans. 16 green jelly beans. How many more green jelly beans? 4 ill in the Quantity diagram and 16 write a number Quantity model. 12? = 4 ifference Home Link 5 2 (Math Masters, p. 127) INPNNT Home onnection hildren connect 6 points with line segments in different ways to form a 6-pointed star and a hexagon. hildren connect other line segments and answer a question about the shapes that are formed. Home Link Master Name ate Time HOM LINK 5 2 Line Segments amily Note In this lesson, your child learned to name points and line segments with capital letters. Using a straightedge, your child drew line segments to create shapes. Provide your child with a ruler, a piece of stiff cardboard, or another object having a straight edge. Observe as your child draws line segments. sk your child to name the shapes that he or she draws in Problems 1 and 2 below (a 6-pointed star and a hexagon). 50 Please return this Home Link to school tomorrow. Use a straightedge to draw line segments. 1. raw these line segments: 2. raw these line segments: 3. raw the following line segments:,,,, How many triangles are there? 6 4. raw points on the back of this page. Label each point with a letter. Use a straightedge to connect the points with line segments to make polygons. Practice = = = 75 Math Masters, p. 127 Lesson

5 Name ate Time LSSON 5 2 Geoboard esigns 1. Use 3 rubber bands to Teaching Master 2. Use 6 rubber bands to 3 ifferentiation Options RINSS Making Geoboard esigns (Math Masters, p. 128) INPNNT 5 15 Min 3. Use 8 rubber bands to 4. Make up your own. I used rubber bands to To explore drawing line segments, have children use rubber bands to make designs on a geoboard. The rubber bands can only be used with a row or column of pins enclosed, so that children are making designs from line segments. (See margin.) They can make shapes or simple designs with intersecting or parallel line segments. This should be an exploration with line segments not an introduction to them. When children are satisfied which each design, they use a straightedge to record their designs on Math Masters, page 128. Math Masters, p. 128 nswers vary. NRIHMNT reating a Line Segment esign (Math Masters, p. 129) INPNNT 5 15 Min To explore using line segments in a design, have children follow directions for drawing line segments in a sequence. s children complete Math Masters, page 129, they should recognize some of the shapes that they draw. Have children describe the process for drawing the shapes. ncourage the use of vocabulary such as point, line segment, endpoint, connect, and shape names. g g Name ate Time LSSON 5 2 Use a straightedge and a crayon. onnect the dots below according to the following pattern: What shape did you make with line segments? Use a different color. onnect the dots again in a different way. ollow this pattern: What shape did you make with line segments? triangle Use a different color. onnect the dots one more time. ollow this pattern: What shapes do you see in your design? olor Teaching Master Line Segment esign Sample answers: hexagons, triangles, star, rectangles Math Masters, p. 129 hexagon Planning head In preparation for the Shapes Museum that will be introduced in Lesson 5-6, collect a few objects or pictures of objects having the following shapes: ylinders: coffee cans, rolls of paper towels, rolls of toilet paper, drinking straws, mugs, fluorescent lightbulbs Spheres: tennis balls, oranges, globes Rectangular prisms: books, cereal boxes, cartons, chalkboard erasers, pictures of a file cabinet, pictures of a bookcase ones: ice cream cones, party hats, conical paper cups, pictures of traffic cones Pyramids: pictures of pyramids or pyramid-shaped roofs ubes: notepaper cubes, regular dice, centimeter cubes, a liter (cubic decimeter) box 326 Unit 5 3- and 2- Shapes